<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>bootstrap</title>
    <link rel="stylesheet" href="bootstrap/css/bootstrap.min.css">
    <script src="jquery/jquery-3.3.1.js"></script>
    <script src="bootstrap/js/bootstrap.min.js"></script>
</head>
<body>
<!--
圆角   .img-rounded
圆形   .img-circle
带有边框的圆角图形   .img-thumbnail
-->

<img class="img-rounded" src="img/001.jpg">
<img class="img-circle" src="img/001.jpg">
<img class="img-thumbnail" src="img/001.jpg">
</body>
</html>